21070115 has 16 divisors (see below), whose sum is σ = 27863136. Its totient is φ = 15168000.

The previous prime is 21070103. The next prime is 21070117. The reversal of 21070115 is 51107012.

It is not a de Polignac number, because 21070115 - 2⁴ = 21070099 is a prime.

It is a super-2 number, since 2×21070115² = 887899492226450, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21070093 and 21070102.

It is not an unprimeable number, because it can be changed into a prime (21070117) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3659 + ... + 7451.

It is an arithmetic number, because the mean of its divisors is an integer number (1741446).

Almost surely, 2^21070115 is an apocalyptic number.

21070115 is a deficient number, since it is larger than the sum of its proper divisors (6793021).

21070115 is a wasteful number, since it uses less digits than its factorization.

21070115 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3910.

The product of its (nonzero) digits is 70, while the sum is 17.

The square root of 21070115 is about 4590.2194936626. The cubic root of 21070115 is about 276.1991272864.

Adding to 21070115 its reverse (51107012), we get a palindrome (72177127).

The spelling of 21070115 in words is "twenty-one million, seventy thousand, one hundred fifteen".